Import outlook mails to windows live mail

Recently i switched from a windows system to a mac.
There i used outlook 2007 as my email client and in mac i am using apple mail. Now the problem where i am stuck is how to import the emails from my windows system to apple mail. I must tell you that there are a lot of emails to be transferred so i do not want to be stuck in transferring through Imap account.

I have posted here coz i need a specific application or software that can process this transfer quickly.
Thanks for your help.